The invention relates to turbine engine rotors fitted with blades made of composite material comprising fiber reinforcement densified with a matrix.
The intended field is that of gas turbine rotors for aeroengines or for industrial turbines.
Proposals have already been made for fabricating turbine engine rotors out of composite material. Reference may be made in particular to international patent application WO 2010/061140 filed jointly by Snecma and Snecma Propulsion Solide. That application describes fabricating a turbine engine blade out of composite material comprising fiber reinforcement densified by a matrix. More precisely, that method presents the feature of the fiber blank made by multilayer weaving incorporating two textures that cross each other so that, after shaping, they form a single-piece fiber preform having a first portion forming a preform for an airfoil and a blade root, and at least one second portion forming a preform for an outer platform of the blade. Thus, after the preform has been densified, it is possible to obtain a composite material blade having fiber reinforcement constituted by the preform and densified by the matrix, and forming a single piece having an outer platform incorporated therein.
Nevertheless, that technique for forming the blade root makes industrial fabrication of the blade more complex and increases fabrication costs because it gives rise to large losses of material and requires handling that is difficult and that slows down the speed of production. In addition, the operating clearances needed between the outer platforms give rise to leaks that reduce the overall performance of the turbine.